And just like that, the Pac-12 regular-season title is firmly up for grabs.

Arizona, bursting at the seams with talent and the popular pick to win the Pac-12 at the beginning of the season, has hit yet another skid. It lost three in a row in November, and now the 13th-ranked Wildcats have dropped their second straight league game, 82-74 to UCLA on Thursday night. It was the first loss at home for Arizona against an unranked team since 2013.

You had to wonder what was going through the Wildcats' minds after a stunning 78-75 loss at Washington last weekend, but Arizona's locker room will likely be at a loss for words after this latest defeat.

Worse, the Wildcats' losses are their foes' gains. Arizona now joins USC with three conference losses, and UCLA finds itself just a game back of the Wildcats in the standings. While UCLA, winners of four straight, and Washington, which had beaten two ranked teams during its own four-game win streak before losing to Oregon Thursday, are pushing forward, Arizona is sliding back into troublesome territory.

It's not like UCLA had some juggernaut performance, either. Instead of frantically pushing the ball at the behest of super fan and ESPN commentator Bill Walton during the broadcast, the Bruins were calm and collected, which seemed to frustrate an Arizona team that could only exchange baskets with the Bruins in the second half.

Thanks to a 17-5 run by UCLA to end the first half, all the Bruins had to do was go into cruise control and make sure the Wildcats didn't get too hot. They contained all-world big man Deandre Ayton as best they could, as he got 16 points and 12 rebounds. Arizona's star guard Allonzo Trier scored 17 and went 3-for-6 from 3-point territory, but UCLA countered with all five of its starters reaching double figures, including captain Aaron Holiday leading the way with 17 points.

The 13th-ranked Wildcats fell behind late in the first half and watched UCLA cruise to victory. Casey Sapio/USA TODAY Sports

UCLA's methodical approach proved to be too balanced and maybe tiresome for a Wildcats team looking to get back on track in a big way against a longtime rival. Unfortunately, the Wildcats spent their time missing easy shots, leaving Bruins way too open.

Arizona, with far superior talent, led for barely more than seven minutes, and its last lead came at 31-30 with 2 minutes, 18 seconds left in the first half. From there, UCLA scored 14 of the next 17 points, including a wild 3 from freshman Jaylen Hands from well beyond the arc as the half expired.

UCLA's juice in the final couple of minutes put enough breathing room between it and Arizona. The second half was full of basket-trading. the Wildcats never found a run and failed to take over at any point -- something championship-caliber teams find ways to do in games like this.

We don't know if this slide has shown us who Arizona really is, but this was supposed to be Sean Miller's most talented team in Tucson. They have a sensational slasher in Trier and a nearly unstoppable and immovable presence down low in Ayton. Yet this is the sixth loss of the season for the Wildcats. One of those losses is to nine-loss SMU and another is to 10-loss Colorado. UCLA is starting to find a bit of a groove, and Washington has been better than expected, but these are losses the Wildcats shouldn't have.

Now the rest of the league's contenders have to be feeling pretty good. This Arizona team looks more beatable and vulnerable heading into the final stretch of the regular season. Maybe it's a quick slide, but it's enough to make the final weeks in the Pac-12 that much more interesting and leaves us wondering if the Wildcats have the killer instinct to finally make a deep NCAA tournament run.